Racking means for circular knitting machines



April 12, 1966 R. PEBERDY BACKING MEANS FOR CIRCULAR KNITTING MACHINES 2 Sheets-Sheet 1 Filed Sept. 1, 1964 April 2, 1966 R. PEBERDY 3,245,231

RACKING MEANS FOR CIRCULAR KNITTING MACHINES Filed Sept. 1, 1964 2 Sheets-Sheet 2 United States Patent 3,245,231 RACKNG MEANS FOR CIRCULAR KNITTING MACHINES Roland Peberdy, Leicester, England, assignor to The Bentley Engineering Company Limited, Leicester, England Filed Sept. 1, 1964, Ser. No. 393,516 Claims priority, application Great Britain, Sept. 2, 1963, 34,512/ 63 Claims. (Cl. 6650) This invention is for improvements in or relating to racking means for circular knitting machines and has for an object to provide improved means for racking or indexing pattern drums.

As is well known drums are used with circular knitting machines for controlling the knitting instrumentalities so as to vary the knitting action according to a predetermined pattern laid out for example by arrangements of pins set up around the peripheries of the drums. A pattern drum is racked round step by step in timed relation to the rotation of the cylinder, usually with one rack occurring at each cylinder rotation. It has in the past been convenient to rack each pattern drum by a cam projection on a ring rotating with the needle cylinder, it being necessary to' ensure that racking occurs at a time when selector cam levers associated with the drum coincide with azone of the cylinder which is devoid of selector butts at that instant. This manner of racking pattern drums in a circular knitting machine as used for knitting hosiery footwear which is organised to knit sometimes by continuous rotation and at other times by reciprocation, introduces difliculties in the case of machines having a plurality of feeding stations, for example having more than two such stations, in association with which patterning drums are distributed round the cylinder circumference and operated 'by a common cam. With such machines some of the pattern drums may be incompletely racked when the cylinder is being reciprocated during the completion of a hosiery article at which period it is generally required for the drums to be racked idly round to the start position ready for commencing patterning on the next hosiery article. The invention seeks to provide means whereby these difiiculties can be overcome.

In accordance with the invention there is provided in a circular knitting machine which is organised to perform knitting sometimes by continuous rotation and at other times by reciprocation, racking means for a pattern drum comprising a rotary cam member and means whereby such cam member is rotated in step with the knitting cycle both when knitting is performed rotationally and when it is performed by reciprocation. The cam member is arranged to operate the racking means on each pattern drum associated with the machine. Thus in the case where a number of pattern drums are distributed around the needle cylinder each will be racked in its correct timed relationship at all times, and the difiiculties aforesaid are avoided.

Conveniently with a rotary cylinder machine the rotary cam member takes the form of a ring surrounding the cylinder and having a cam projection to effect the racking movements, which ring instead of being fixed to the cylinder is so mounted as to be rotatable relatively thereto. Said ring is driven by gearing from driving mechanism of the cylinder to rotate at all times at a speed which is in step with the rotations of the cylinder.

The accompanying drawings illustrate by way of example a convenient form of construction embodying the foregoing and other provisions in accordance with the invention. This construction will now be described with reference to the drawings in which:

FIGURE 1 is an elevation view showing part of a knitting machine from the rear, indicating how the drive to the racking cam is obtained,

FIGURE 2 is a plan view of FIGURE 1 taken in cross section on the line X-X, and

FIGURE 3 is a cross-sectional elevation view taken on the line AA in FIGURE 2 and on a scale larger than that of FIGURE 2.

The two walls 1 and 2 of the frame or gear box can be seen in FIGURE 1 and these support a bed plate 3 which carries a needle cylinder 4, and associated cam and jack box assembly shown diagrammatically at 5. The centre line of the main drive shaft is shown at 6. This main shaft has a bevel gear 7 secured to one end and spur gears 8 and 9 are freely mounted on it. Each spur gear has clutch dogs formed thereon in a position to be engaged, one or the other, by mating dogs formed on each side of a clutch body 10 which is disposed between the two gears. The clutch body 10 is keyed to the main shaft by splines formed in its bore, it is thus free to be slid to the left or right to be driven by either gear 8 or gear 9. Gear 8 isitself driven through gearing (not shown) in a constant direction whilst gear 9 is meshed with the teeth of a rocking quadrant (also not shown) and is thus always reciprocating. When making heels and toes the clutch body 10 is engaged with gear 9 and thus the bevel wheel 7 is caused to reciprocate. When making the leg and foot the clutch body 10 is engaged with gear 8 and bevel gear 7 is rotated in one direction only.

Bevel gear 7 is meshed with gear 11 which is keyed to the vertical drive shaft 12. FIGURE 3 shows bevel gear 11 and also above it a spur gear 13 which is also keyed to the shaft. Gear 13 has a sleeve portion 13a which is journalled in a ball race 14 which provides a bearing for the vertical shaft assembly. The ball race 14 is mounted in a bracket 15 secured by screws such as 16 to the underside of the bed plate 3. A spacer 38 is provided to counteract the thrust of the bevel gears 7 and 11. Spur gear 13 is meshed with the cylinder carriage gear 17 to which the needle cylinder 4 is secured by screws such as 19. The cylinder 4 is thus driven either in rotation or reciprocation as described, by bevel gear 7 through the vertical shaft 12.

The pattern drum racking cam 20 is located on a support ring 21, FIGURE 3 which encircles the needle cylinder. This support ring is secured by screws such as 22 to the top surface of a gear ring 23 which is itself located between a plate 24 and the cylinder gear 17 to which the plate 24 is secured by screws such as 25. As can be seen in FIGURE 3 the gear ring 23 is bevelled at 23a to reduce friction and allow the gear ring 23 to revolve freely between the cylinder gear 17 and the plate 24. This is important because while the cylinder gear is reciprocat v ing in the heel and toe, the gear ring 23 and attached support ring 21 and cam 20 will be driven in one direction only. The drive to cam 20 is obtained as follows.

As shown in FIGURE 1 the spur gear 8 which is con stantly revolving, drives through a train of gears 26, 27

and 28 a shaft 29 which is carried in hearings in the two walls 36 and 31 (shown broken) of a support bracket for yarn feeding attachments. For reasons to be stated later, the gear 28 is freely mounted on one end of the shaft 29, but it is clamped to a flanged collar 36 by screws 37 and as the collar 36 is secured to the shaft 29 the drive is transmitted from the gear 28 via the collar 36. Secured to the other end of shaft 29 is a bevel gear 32 which drives a mating gear 33 which is freely mounted on the vertical shaft 12. The bevel gear 33 is secured to a spur gear 34 and, as can be seen in FIGURE 3, the spur gear is located between the face 3a of a recess formed in the bed plate 3 and the face 13b of the gear 13. Because the bevel and spur gear assembly (items 33 and 34) must be free to revolve when the vertical shaft 12 is reciprocating, the bearing surfaces 3a and 13b are reduced to a minimum and clearance is provided for all other surfaces of the gear 34. An oil groove 35 is provided in the bevel gear 33. The spur gear 34 meshes with gear 23 to complete the drive to the attached ring 21 and cam 20.

FIGURE 2 shows how conveniently the cam 20 is disposed with respect to the pattern drum assemblies which are indicated diagrammatically by chain dotted lines at 40. An important feature of the invention is the ability to adjust the angular relationship of the cam 20 with respect to the needle cylinder 4. This can be done simply by slackening off the screws 37 which clamp the gear 28 (FIGURE 1) to the flanged collar 36 and rotating the collar with respect to the gear. The screw holes in the flange are slotted to permit this relative adjustment between gear and flange. By rotating the collar and shaft 29 the bevel gear 32 is turned, thus turning the cam 20 relatively to the needle cylinder 4. Thus it is not necessary to gain access to the screws which attach the cam to the support ring 21 in order to adjust the timing of this cam.

I claim:

1. In a circular knitting machine organized to perform knitting sometimes by continuous rotation and at other times by reciprocation, the provision of pattern drum racking means comprising a rotary cam member and means for rotating said cam member in step with the knitting cycle both when knitting is performed rotationally and when it is performed by reciprocation, and a plurality of pattern drums spaced circumferentially around the axis of the needle circle and having said rotary cam member arranged to effect racking of said pattern drums in turn in correct timed relationship.

2. In a circular knitting machine organized to perform knitting sometimes by continuous rotation and at other times by reciprocation, the provision of pattern drum racking means comprising a rotary cam member and means for rotating said cam member in step with the knitting cycle both when knitting is performed rotationally and when it is performed by reciprocation, and a rotary needle cylinder, wherein said rotary cam member is constituted by a ring surrounding the needle cylinder and provided with a cam projection to effect racking movements, and having means mounting said ring for rotation relatively to the needle cylinder.

3. Racking means according to claim 2, comprising driving mechanism for said needle cylinder and gearing forming a driving connection between said driving mechanism and the cam ring to rotate the cam ring at all times at a speed which is in step with the rotations of the needle cylinder.

4. Racking means according to claim 2, comprising bearings for mounting the rotary cam ring around the cylinder, a spur gear for driving said cam ring and means coupling the spur gear to the driving means for rotating the cylinder continuously.

5. Racking means according to claim 4 comprising means securing the spur gear to the cam ring, an upstanding spindle, a gear wheel carried on the upstanding spindle and meshing with said spur gear, a horizontal shaft, means gearing the horizontal shaft to the driving means for the cylinder, and bevel gearing coupling said hori zontal shaft to said gear :wheel on the upstanding spindle.

6. Racking means according to claim 5 wherein the d upstanding spindle is the spindle of a gear drive to the needle cylinder, and the gear coupled to the spur gear of the cam ring is freely rotatable on said upstanding spindle.

7. Racking means according to claim 2 comprising a clutch spindle, an oscillating gear, a continuously rotating gear, clutch means for coupling the needle cylinder alternatively to said oscillating gear and said continuously rotating gear, and driving means for driving the cam ring from said continuously rotating gear.

8. In a circular knitting machine organised to perform knitting sometimes by continuous rotation and at other times by reciprocation, the provision of pattern drum racking means comprising a rotary cam member, driving means for said cam member, a continuously rotating driving member rotated in step with the knitting cycle during both rotational and reciprocatory knitting, means coupling said driving member to said driving means and means permitting angular adjustment of said rotary cam member about its axis of rotation relatively to said driving member for adjustment of the timing of the operation of the parts racked by the action of the rotary cam member.

9. Racking means according to claim 8 comprising the combination with a rotary needle cylinder of a cam ring rotatable around said cylinder and constituting the said rotary cam member, a spur gear extending around and secured to said cam ring, an upstanding spindle, a gear wheel on said upstanding spindle in mesh with said spur gear, a bevel gear connected to said gear wheel, a horizontal shaft, means gearing said horizontal shaft to the driving means for the cylinder, a second bevel gear secured to said horizontal shaft and meshing with the first said bevel gear, a driving gear carried on said horizontal shaft and positioned at a position thereon spaced outwardly from the needle cylinder for coupling said horizontal shaft to the driving means, and means permitting angular adjustment of said driving gear on said horizontal shaft whereby to adjust the timing of the rotary cam member.

10. In a circular knitting machine organised to perform knitting sometimes by continuous rotation and at other times by reciprocation, the provision of pattern drum racking means comprising the combination with a rotary needle cylinder of a rotary cam ring extending around the axis of the cylinder and provided with an outwardly directed cam projection, means mounting said rotary cam ring for rotation independently of the needle cylinder, driving means for the needle cylinder comprising a continuously rotated member, an oscillating member and clutch means for coupling the cylinder alternatively to said continuously rotating member and said oscillating member, and means for driving said cam ring from said continuously rotating member.

References Cited by the Examiner UNITED STATES PATENTS 2,727,373 12/1955 Dowell 66-50 X 3,067,599 12/1962 Mazzi 66-50 3,086,378 4/1963 Azzolari 6650 DONALD W. PARKER, Primary Examiner.

P. C. FAW, Assistant Examiner. 

1. IN A CIRCULAR KNITTING MACHINE ORGANIZED TO PERFORM KNITTING SOMETIMES BY CONTINUOUS ROTATION AND AT OTHER TIMES BY RECIPROCATION, THE PROVISION OF PATTERN DRUM RACKING MEANS COMPRISING A ROTARY CAM MEMBER AND MEANS FOR ROTATING SAID CAM MEMBER IN STEP WITH THE KNITTING CYCLE BOTH WHEN KNITTING IS PERFORMED ROTATIONALLY AND WHEN IT IS PERFORMED BY RECIPROCATION, AND A PLURALITY OF PATTERN DRUMS SPACED CIRCUMFERENTIALLY 